OSCL-LXR linux-6.0.1/​drivers/​acpi/​device_pm.c	Source navigation Diff markup Identifier search General search
	Version: linux-6.0.1 spark-3.0.0 hadoop-3.2.0-src hadoop-3.3.0-src spark-2.4.7 linux-4.15.13 hadoop-2.7.4-src Revert   Change

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * drivers/acpi/device_pm.c - ACPI device power management routines.
  *
  * Copyright (C) 2012, Intel Corp.
  * Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
  *
  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  *
  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  */
 
 #define pr_fmt(fmt) "PM: " fmt
 
 #include <linux/acpi.h>
 #include <linux/export.h>
 #include <linux/mutex.h>
 #include <linux/pm_qos.h>
 #include <linux/pm_domain.h>
 #include <linux/pm_runtime.h>
 #include <linux/suspend.h>
 
 #include "fan.h"
 #include "internal.h"
 
 /**
  * acpi_power_state_string - String representation of ACPI device power state.
  * @state: ACPI device power state to return the string representation of.
  */
 const char *acpi_power_state_string(int state)
 {
     switch (state) {
     case ACPI_STATE_D0:
         return "D0";
     case ACPI_STATE_D1:
         return "D1";
     case ACPI_STATE_D2:
         return "D2";
     case ACPI_STATE_D3_HOT:
         return "D3hot";
     case ACPI_STATE_D3_COLD:
         return "D3cold";
     default:
         return "(unknown)";
     }
 }
 
 static int acpi_dev_pm_explicit_get(struct acpi_device *device, int *state)
 {
     unsigned long long psc;
     acpi_status status;
 
     status = acpi_evaluate_integer(device->handle, "_PSC", NULL, &psc);
     if (ACPI_FAILURE(status))
         return -ENODEV;
 
     *state = psc;
     return 0;
 }
 
 /**
  * acpi_device_get_power - Get power state of an ACPI device.
  * @device: Device to get the power state of.
  * @state: Place to store the power state of the device.
  *
  * This function does not update the device's power.state field, but it may
  * update its parent's power.state field (when the parent's power state is
  * unknown and the device's power state turns out to be D0).
  *
  * Also, it does not update power resource reference counters to ensure that
  * the power state returned by it will be persistent and it may return a power
  * state shallower than previously set by acpi_device_set_power() for @device
  * (if that power state depends on any power resources).
  */
 int acpi_device_get_power(struct acpi_device *device, int *state)
 {
     int result = ACPI_STATE_UNKNOWN;
     int error;
 
     if (!device || !state)
         return -EINVAL;
 
     if (!device->flags.power_manageable) {
         /* TBD: Non-recursive algorithm for walking up hierarchy. */
         *state = device->parent ?
             device->parent->power.state : ACPI_STATE_D0;
         goto out;
     }
 
     /*
      * Get the device's power state from power resources settings and _PSC,
      * if available.
      */
     if (device->power.flags.power_resources) {
         error = acpi_power_get_inferred_state(device, &result);
         if (error)
             return error;
     }
     if (device->power.flags.explicit_get) {
         int psc;
 
         error = acpi_dev_pm_explicit_get(device, &psc);
         if (error)
             return error;
 
         /*
          * The power resources settings may indicate a power state
          * shallower than the actual power state of the device, because
          * the same power resources may be referenced by other devices.
          *
          * For systems predating ACPI 4.0 we assume that D3hot is the
          * deepest state that can be supported.
          */
         if (psc > result && psc < ACPI_STATE_D3_COLD)
             result = psc;
         else if (result == ACPI_STATE_UNKNOWN)
             result = psc > ACPI_STATE_D2 ? ACPI_STATE_D3_HOT : psc;
     }
 
     /*
      * If we were unsure about the device parent's power state up to this
      * point, the fact that the device is in D0 implies that the parent has
      * to be in D0 too, except if ignore_parent is set.
      */
     if (!device->power.flags.ignore_parent && device->parent
         && device->parent->power.state == ACPI_STATE_UNKNOWN
         && result == ACPI_STATE_D0)
         device->parent->power.state = ACPI_STATE_D0;
 
     *state = result;
 
  out:
     acpi_handle_debug(device->handle, "Power state: %s\n",
               acpi_power_state_string(*state));
 
     return 0;
 }
 
 static int acpi_dev_pm_explicit_set(struct acpi_device *adev, int state)
 {
     if (adev->power.states[state].flags.explicit_set) {
         char method[5] = { '_', 'P', 'S', '0' + state, '\0' };
         acpi_status status;
 
         status = acpi_evaluate_object(adev->handle, method, NULL, NULL);
         if (ACPI_FAILURE(status))
             return -ENODEV;
     }
     return 0;
 }
 
 /**
  * acpi_device_set_power - Set power state of an ACPI device.
  * @device: Device to set the power state of.
  * @state: New power state to set.
  *
  * Callers must ensure that the device is power manageable before using this
  * function.
  */
 int acpi_device_set_power(struct acpi_device *device, int state)
 {
     int target_state = state;
     int result = 0;
 
     if (!device || !device->flags.power_manageable
         || (state < ACPI_STATE_D0) || (state > ACPI_STATE_D3_COLD))
         return -EINVAL;
 
     acpi_handle_debug(device->handle, "Power state change: %s -> %s\n",
               acpi_power_state_string(device->power.state),
               acpi_power_state_string(state));
 
     /* Make sure this is a valid target state */
 
     /* There is a special case for D0 addressed below. */
     if (state > ACPI_STATE_D0 && state == device->power.state)
         goto no_change;
 
     if (state == ACPI_STATE_D3_COLD) {
         /*
          * For transitions to D3cold we need to execute _PS3 and then
          * possibly drop references to the power resources in use.
          */
         state = ACPI_STATE_D3_HOT;
         /* If D3cold is not supported, use D3hot as the target state. */
         if (!device->power.states[ACPI_STATE_D3_COLD].flags.valid)
             target_state = state;
     } else if (!device->power.states[state].flags.valid) {
         acpi_handle_debug(device->handle, "Power state %s not supported\n",
                   acpi_power_state_string(state));
         return -ENODEV;
     }
 
     if (!device->power.flags.ignore_parent && device->parent &&
         state < device->parent->power.state) {
         acpi_handle_debug(device->handle,
                   "Cannot transition to %s for parent in %s\n",
                   acpi_power_state_string(state),
                   acpi_power_state_string(device->parent->power.state));
         return -ENODEV;
     }
 
     /*
      * Transition Power
      * ----------------
      * In accordance with ACPI 6, _PSx is executed before manipulating power
      * resources, unless the target state is D0, in which case _PS0 is
      * supposed to be executed after turning the power resources on.
      */
     if (state > ACPI_STATE_D0) {
         /*
          * According to ACPI 6, devices cannot go from lower-power
          * (deeper) states to higher-power (shallower) states.
          */
         if (state < device->power.state) {
             acpi_handle_debug(device->handle,
                       "Cannot transition from %s to %s\n",
                       acpi_power_state_string(device->power.state),
                       acpi_power_state_string(state));
             return -ENODEV;
         }
 
         /*
          * If the device goes from D3hot to D3cold, _PS3 has been
          * evaluated for it already, so skip it in that case.
          */
         if (device->power.state < ACPI_STATE_D3_HOT) {
             result = acpi_dev_pm_explicit_set(device, state);
             if (result)
                 goto end;
         }
 
         if (device->power.flags.power_resources)
             result = acpi_power_transition(device, target_state);
     } else {
         int cur_state = device->power.state;
 
         if (device->power.flags.power_resources) {
             result = acpi_power_transition(device, ACPI_STATE_D0);
             if (result)
                 goto end;
         }
 
         if (cur_state == ACPI_STATE_D0) {
             int psc;
 
             /* Nothing to do here if _PSC is not present. */
             if (!device->power.flags.explicit_get)
                 goto no_change;
 
             /*
              * The power state of the device was set to D0 last
              * time, but that might have happened before a
              * system-wide transition involving the platform
              * firmware, so it may be necessary to evaluate _PS0
              * for the device here.  However, use extra care here
              * and evaluate _PSC to check the device's current power
              * state, and only invoke _PS0 if the evaluation of _PSC
              * is successful and it returns a power state different
              * from D0.
              */
             result = acpi_dev_pm_explicit_get(device, &psc);
             if (result || psc == ACPI_STATE_D0)
                 goto no_change;
         }
 
         result = acpi_dev_pm_explicit_set(device, ACPI_STATE_D0);
     }
 
 end:
     if (result) {
         acpi_handle_debug(device->handle,
                   "Failed to change power state to %s\n",
                   acpi_power_state_string(target_state));
     } else {
         device->power.state = target_state;
         acpi_handle_debug(device->handle, "Power state changed to %s\n",
                   acpi_power_state_string(target_state));
     }
 
     return result;
 
 no_change:
     acpi_handle_debug(device->handle, "Already in %s\n",
               acpi_power_state_string(state));
     return 0;
 }
 EXPORT_SYMBOL(acpi_device_set_power);
 
 int acpi_bus_set_power(acpi_handle handle, int state)
 {
     struct acpi_device *device = acpi_fetch_acpi_dev(handle);
 
     if (device)
         return acpi_device_set_power(device, state);
 
     return -ENODEV;
 }
 EXPORT_SYMBOL(acpi_bus_set_power);
 
 int acpi_bus_init_power(struct acpi_device *device)
 {
     int state;
     int result;
 
     if (!device)
         return -EINVAL;
 
     device->power.state = ACPI_STATE_UNKNOWN;
     if (!acpi_device_is_present(device)) {
         device->flags.initialized = false;
         return -ENXIO;
     }
 
     result = acpi_device_get_power(device, &state);
     if (result)
         return result;
 
     if (state < ACPI_STATE_D3_COLD && device->power.flags.power_resources) {
         /* Reference count the power resources. */
         result = acpi_power_on_resources(device, state);
         if (result)
             return result;
 
         if (state == ACPI_STATE_D0) {
             /*
              * If _PSC is not present and the state inferred from
              * power resources appears to be D0, it still may be
              * necessary to execute _PS0 at this point, because
              * another device using the same power resources may
              * have been put into D0 previously and that's why we
              * see D0 here.
              */
             result = acpi_dev_pm_explicit_set(device, state);
             if (result)
                 return result;
         }
     } else if (state == ACPI_STATE_UNKNOWN) {
         /*
          * No power resources and missing _PSC?  Cross fingers and make
          * it D0 in hope that this is what the BIOS put the device into.
          * [We tried to force D0 here by executing _PS0, but that broke
          * Toshiba P870-303 in a nasty way.]
          */
         state = ACPI_STATE_D0;
     }
     device->power.state = state;
     return 0;
 }
 
 /**
  * acpi_device_fix_up_power - Force device with missing _PSC into D0.
  * @device: Device object whose power state is to be fixed up.
  *
  * Devices without power resources and _PSC, but having _PS0 and _PS3 defined,
  * are assumed to be put into D0 by the BIOS.  However, in some cases that may
  * not be the case and this function should be used then.
  */
 int acpi_device_fix_up_power(struct acpi_device *device)
 {
     int ret = 0;
 
     if (!device->power.flags.power_resources
         && !device->power.flags.explicit_get
         && device->power.state == ACPI_STATE_D0)
         ret = acpi_dev_pm_explicit_set(device, ACPI_STATE_D0);
 
     return ret;
 }
 EXPORT_SYMBOL_GPL(acpi_device_fix_up_power);
 
 static int fix_up_power_if_applicable(struct acpi_device *adev, void *not_used)
 {
     if (adev->status.present && adev->status.enabled)
         acpi_device_fix_up_power(adev);
 
     return 0;
 }
 
 /**
  * acpi_device_fix_up_power_extended - Force device and its children into D0.
  * @adev: Parent device object whose power state is to be fixed up.
  *
  * Call acpi_device_fix_up_power() for @adev and its children so long as they
  * are reported as present and enabled.
  */
 void acpi_device_fix_up_power_extended(struct acpi_device *adev)
 {
     acpi_device_fix_up_power(adev);
     acpi_dev_for_each_child(adev, fix_up_power_if_applicable, NULL);
 }
 EXPORT_SYMBOL_GPL(acpi_device_fix_up_power_extended);
 
 int acpi_device_update_power(struct acpi_device *device, int *state_p)
 {
     int state;
     int result;
 
     if (device->power.state == ACPI_STATE_UNKNOWN) {
         result = acpi_bus_init_power(device);
         if (!result && state_p)
             *state_p = device->power.state;
 
         return result;
     }
 
     result = acpi_device_get_power(device, &state);
     if (result)
         return result;
 
     if (state == ACPI_STATE_UNKNOWN) {
         state = ACPI_STATE_D0;
         result = acpi_device_set_power(device, state);
         if (result)
             return result;
     } else {
         if (device->power.flags.power_resources) {
             /*
              * We don't need to really switch the state, bu we need
              * to update the power resources' reference counters.
              */
             result = acpi_power_transition(device, state);
             if (result)
                 return result;
         }
         device->power.state = state;
     }
     if (state_p)
         *state_p = state;
 
     return 0;
 }
 EXPORT_SYMBOL_GPL(acpi_device_update_power);
 
 int acpi_bus_update_power(acpi_handle handle, int *state_p)
 {
     struct acpi_device *device = acpi_fetch_acpi_dev(handle);
 
     if (device)
         return acpi_device_update_power(device, state_p);
 
     return -ENODEV;
 }
 EXPORT_SYMBOL_GPL(acpi_bus_update_power);
 
 bool acpi_bus_power_manageable(acpi_handle handle)
 {
     struct acpi_device *device = acpi_fetch_acpi_dev(handle);
 
     return device && device->flags.power_manageable;
 }
 EXPORT_SYMBOL(acpi_bus_power_manageable);
 
 static int acpi_power_up_if_adr_present(struct acpi_device *adev, void *not_used)
 {
     if (!(adev->flags.power_manageable && adev->pnp.type.bus_address))
         return 0;
 
     acpi_handle_debug(adev->handle, "Power state: %s\n",
               acpi_power_state_string(adev->power.state));
 
     if (adev->power.state == ACPI_STATE_D3_COLD)
         return acpi_device_set_power(adev, ACPI_STATE_D0);
 
     return 0;
 }
 
 /**
  * acpi_dev_power_up_children_with_adr - Power up childres with valid _ADR
  * @adev: Parent ACPI device object.
  *
  * Change the power states of the direct children of @adev that are in D3cold
  * and hold valid _ADR objects to D0 in order to allow bus (e.g. PCI)
  * enumeration code to access them.
  */
 void acpi_dev_power_up_children_with_adr(struct acpi_device *adev)
 {
     acpi_dev_for_each_child(adev, acpi_power_up_if_adr_present, NULL);
 }
 
 #ifdef CONFIG_PM
 static DEFINE_MUTEX(acpi_pm_notifier_lock);
 static DEFINE_MUTEX(acpi_pm_notifier_install_lock);
 
 void acpi_pm_wakeup_event(struct device *dev)
 {
     pm_wakeup_dev_event(dev, 0, acpi_s2idle_wakeup());
 }
 EXPORT_SYMBOL_GPL(acpi_pm_wakeup_event);
 
 static void acpi_pm_notify_handler(acpi_handle handle, u32 val, void *not_used)
 {
     struct acpi_device *adev;
 
     if (val != ACPI_NOTIFY_DEVICE_WAKE)
         return;
 
     acpi_handle_debug(handle, "Wake notify\n");
 
     adev = acpi_bus_get_acpi_device(handle);
     if (!adev)
         return;
 
     mutex_lock(&acpi_pm_notifier_lock);
 
     if (adev->wakeup.flags.notifier_present) {
         pm_wakeup_ws_event(adev->wakeup.ws, 0, acpi_s2idle_wakeup());
         if (adev->wakeup.context.func) {
             acpi_handle_debug(handle, "Running %pS for %s\n",
                       adev->wakeup.context.func,
                       dev_name(adev->wakeup.context.dev));
             adev->wakeup.context.func(&adev->wakeup.context);
         }
     }
 
     mutex_unlock(&acpi_pm_notifier_lock);
 
     acpi_bus_put_acpi_device(adev);
 }
 
 /**
  * acpi_add_pm_notifier - Register PM notify handler for given ACPI device.
  * @adev: ACPI device to add the notify handler for.
  * @dev: Device to generate a wakeup event for while handling the notification.
  * @func: Work function to execute when handling the notification.
  *
  * NOTE: @adev need not be a run-wake or wakeup device to be a valid source of
  * PM wakeup events.  For example, wakeup events may be generated for bridges
  * if one of the devices below the bridge is signaling wakeup, even if the
  * bridge itself doesn't have a wakeup GPE associated with it.
  */
 acpi_status acpi_add_pm_notifier(struct acpi_device *adev, struct device *dev,
             void (*func)(struct acpi_device_wakeup_context *context))
 {
     acpi_status status = AE_ALREADY_EXISTS;
 
     if (!dev && !func)
         return AE_BAD_PARAMETER;
 
     mutex_lock(&acpi_pm_notifier_install_lock);
 
     if (adev->wakeup.flags.notifier_present)
         goto out;
 
     status = acpi_install_notify_handler(adev->handle, ACPI_SYSTEM_NOTIFY,
                          acpi_pm_notify_handler, NULL);
     if (ACPI_FAILURE(status))
         goto out;
 
     mutex_lock(&acpi_pm_notifier_lock);
     adev->wakeup.ws = wakeup_source_register(&adev->dev,
                          dev_name(&adev->dev));
     adev->wakeup.context.dev = dev;
     adev->wakeup.context.func = func;
     adev->wakeup.flags.notifier_present = true;
     mutex_unlock(&acpi_pm_notifier_lock);
 
  out:
     mutex_unlock(&acpi_pm_notifier_install_lock);
     return status;
 }
 
 /**
  * acpi_remove_pm_notifier - Unregister PM notifier from given ACPI device.
  * @adev: ACPI device to remove the notifier from.
  */
 acpi_status acpi_remove_pm_notifier(struct acpi_device *adev)
 {
     acpi_status status = AE_BAD_PARAMETER;
 
     mutex_lock(&acpi_pm_notifier_install_lock);
 
     if (!adev->wakeup.flags.notifier_present)
         goto out;
 
     status = acpi_remove_notify_handler(adev->handle,
                         ACPI_SYSTEM_NOTIFY,
                         acpi_pm_notify_handler);
     if (ACPI_FAILURE(status))
         goto out;
 
     mutex_lock(&acpi_pm_notifier_lock);
     adev->wakeup.context.func = NULL;
     adev->wakeup.context.dev = NULL;
     wakeup_source_unregister(adev->wakeup.ws);
     adev->wakeup.flags.notifier_present = false;
     mutex_unlock(&acpi_pm_notifier_lock);
 
  out:
     mutex_unlock(&acpi_pm_notifier_install_lock);
     return status;
 }
 
 bool acpi_bus_can_wakeup(acpi_handle handle)
 {
     struct acpi_device *device = acpi_fetch_acpi_dev(handle);
 
     return device && device->wakeup.flags.valid;
 }
 EXPORT_SYMBOL(acpi_bus_can_wakeup);
 
 bool acpi_pm_device_can_wakeup(struct device *dev)
 {
     struct acpi_device *adev = ACPI_COMPANION(dev);
 
     return adev ? acpi_device_can_wakeup(adev) : false;
 }
 
 /**
  * acpi_dev_pm_get_state - Get preferred power state of ACPI device.
  * @dev: Device whose preferred target power state to return.
  * @adev: ACPI device node corresponding to @dev.
  * @target_state: System state to match the resultant device state.
  * @d_min_p: Location to store the highest power state available to the device.
  * @d_max_p: Location to store the lowest power state available to the device.
  *
  * Find the lowest power (highest number) and highest power (lowest number) ACPI
  * device power states that the device can be in while the system is in the
  * state represented by @target_state.  Store the integer numbers representing
  * those stats in the memory locations pointed to by @d_max_p and @d_min_p,
  * respectively.
  *
  * Callers must ensure that @dev and @adev are valid pointers and that @adev
  * actually corresponds to @dev before using this function.
  *
  * Returns 0 on success or -ENODATA when one of the ACPI methods fails or
  * returns a value that doesn't make sense.  The memory locations pointed to by
  * @d_max_p and @d_min_p are only modified on success.
  */
 static int acpi_dev_pm_get_state(struct device *dev, struct acpi_device *adev,
                  u32 target_state, int *d_min_p, int *d_max_p)
 {
     char method[] = { '_', 'S', '0' + target_state, 'D', '\0' };
     acpi_handle handle = adev->handle;
     unsigned long long ret;
     int d_min, d_max;
     bool wakeup = false;
     bool has_sxd = false;
     acpi_status status;
 
     /*
      * If the system state is S0, the lowest power state the device can be
      * in is D3cold, unless the device has _S0W and is supposed to signal
      * wakeup, in which case the return value of _S0W has to be used as the
      * lowest power state available to the device.
      */
     d_min = ACPI_STATE_D0;
     d_max = ACPI_STATE_D3_COLD;
 
     /*
      * If present, _SxD methods return the minimum D-state (highest power
      * state) we can use for the corresponding S-states.  Otherwise, the
      * minimum D-state is D0 (ACPI 3.x).
      */
     if (target_state > ACPI_STATE_S0) {
         /*
          * We rely on acpi_evaluate_integer() not clobbering the integer
          * provided if AE_NOT_FOUND is returned.
          */
         ret = d_min;
         status = acpi_evaluate_integer(handle, method, NULL, &ret);
         if ((ACPI_FAILURE(status) && status != AE_NOT_FOUND)
             || ret > ACPI_STATE_D3_COLD)
             return -ENODATA;
 
         /*
          * We need to handle legacy systems where D3hot and D3cold are
          * the same and 3 is returned in both cases, so fall back to
          * D3cold if D3hot is not a valid state.
          */
         if (!adev->power.states[ret].flags.valid) {
             if (ret == ACPI_STATE_D3_HOT)
                 ret = ACPI_STATE_D3_COLD;
             else
                 return -ENODATA;
         }
 
         if (status == AE_OK)
             has_sxd = true;
 
         d_min = ret;
         wakeup = device_may_wakeup(dev) && adev->wakeup.flags.valid
             && adev->wakeup.sleep_state >= target_state;
     } else {
         wakeup = adev->wakeup.flags.valid;
     }
 
     /*
      * If _PRW says we can wake up the system from the target sleep state,
      * the D-state returned by _SxD is sufficient for that (we assume a
      * wakeup-aware driver if wake is set).  Still, if _SxW exists
      * (ACPI 3.x), it should return the maximum (lowest power) D-state that
      * can wake the system.  _S0W may be valid, too.
      */
     if (wakeup) {
         method[3] = 'W';
         status = acpi_evaluate_integer(handle, method, NULL, &ret);
         if (status == AE_NOT_FOUND) {
             /* No _SxW. In this case, the ACPI spec says that we
              * must not go into any power state deeper than the
              * value returned from _SxD.
              */
             if (has_sxd && target_state > ACPI_STATE_S0)
                 d_max = d_min;
         } else if (ACPI_SUCCESS(status) && ret <= ACPI_STATE_D3_COLD) {
             /* Fall back to D3cold if ret is not a valid state. */
             if (!adev->power.states[ret].flags.valid)
                 ret = ACPI_STATE_D3_COLD;
 
             d_max = ret > d_min ? ret : d_min;
         } else {
             return -ENODATA;
         }
     }
 
     if (d_min_p)
         *d_min_p = d_min;
 
     if (d_max_p)
         *d_max_p = d_max;
 
     return 0;
 }
 
 /**
  * acpi_pm_device_sleep_state - Get preferred power state of ACPI device.
  * @dev: Device whose preferred target power state to return.
  * @d_min_p: Location to store the upper limit of the allowed states range.
  * @d_max_in: Deepest low-power state to take into consideration.
  * Return value: Preferred power state of the device on success, -ENODEV
  * if there's no 'struct acpi_device' for @dev, -EINVAL if @d_max_in is
  * incorrect, or -ENODATA on ACPI method failure.
  *
  * The caller must ensure that @dev is valid before using this function.
  */
 int acpi_pm_device_sleep_state(struct device *dev, int *d_min_p, int d_max_in)
 {
     struct acpi_device *adev;
     int ret, d_min, d_max;
 
     if (d_max_in < ACPI_STATE_D0 || d_max_in > ACPI_STATE_D3_COLD)
         return -EINVAL;
 
     if (d_max_in > ACPI_STATE_D2) {
         enum pm_qos_flags_status stat;
 
         stat = dev_pm_qos_flags(dev, PM_QOS_FLAG_NO_POWER_OFF);
         if (stat == PM_QOS_FLAGS_ALL)
             d_max_in = ACPI_STATE_D2;
     }
 
     adev = ACPI_COMPANION(dev);
     if (!adev) {
         dev_dbg(dev, "ACPI companion missing in %s!\n", __func__);
         return -ENODEV;
     }
 
     ret = acpi_dev_pm_get_state(dev, adev, acpi_target_system_state(),
                     &d_min, &d_max);
     if (ret)
         return ret;
 
     if (d_max_in < d_min)
         return -EINVAL;
 
     if (d_max > d_max_in) {
         for (d_max = d_max_in; d_max > d_min; d_max--) {
             if (adev->power.states[d_max].flags.valid)
                 break;
         }
     }
 
     if (d_min_p)
         *d_min_p = d_min;
 
     return d_max;
 }
 EXPORT_SYMBOL(acpi_pm_device_sleep_state);
 
 /**
  * acpi_pm_notify_work_func - ACPI devices wakeup notification work function.
  * @context: Device wakeup context.
  */
 static void acpi_pm_notify_work_func(struct acpi_device_wakeup_context *context)
 {
     struct device *dev = context->dev;
 
     if (dev) {
         pm_wakeup_event(dev, 0);
         pm_request_resume(dev);
     }
 }
 
 static DEFINE_MUTEX(acpi_wakeup_lock);
 
 static int __acpi_device_wakeup_enable(struct acpi_device *adev,
                        u32 target_state)
 {
     struct acpi_device_wakeup *wakeup = &adev->wakeup;
     acpi_status status;
     int error = 0;
 
     mutex_lock(&acpi_wakeup_lock);
 
     /*
      * If the device wakeup power is already enabled, disable it and enable
      * it again in case it depends on the configuration of subordinate
      * devices and the conditions have changed since it was enabled last
      * time.
      */
     if (wakeup->enable_count > 0)
         acpi_disable_wakeup_device_power(adev);
 
     error = acpi_enable_wakeup_device_power(adev, target_state);
     if (error) {
         if (wakeup->enable_count > 0) {
             acpi_disable_gpe(wakeup->gpe_device, wakeup->gpe_number);
             wakeup->enable_count = 0;
         }
         goto out;
     }
 
     if (wakeup->enable_count > 0)
         goto inc;
 
     status = acpi_enable_gpe(wakeup->gpe_device, wakeup->gpe_number);
     if (ACPI_FAILURE(status)) {
         acpi_disable_wakeup_device_power(adev);
         error = -EIO;
         goto out;
     }
 
     acpi_handle_debug(adev->handle, "GPE%2X enabled for wakeup\n",
               (unsigned int)wakeup->gpe_number);
 
 inc:
     if (wakeup->enable_count < INT_MAX)
         wakeup->enable_count++;
     else
         acpi_handle_info(adev->handle, "Wakeup enable count out of bounds!\n");
 
 out:
     mutex_unlock(&acpi_wakeup_lock);
     return error;
 }
 
 /**
  * acpi_device_wakeup_enable - Enable wakeup functionality for device.
  * @adev: ACPI device to enable wakeup functionality for.
  * @target_state: State the system is transitioning into.
  *
  * Enable the GPE associated with @adev so that it can generate wakeup signals
  * for the device in response to external (remote) events and enable wakeup
  * power for it.
  *
  * Callers must ensure that @adev is a valid ACPI device node before executing
  * this function.
  */
 static int acpi_device_wakeup_enable(struct acpi_device *adev, u32 target_state)
 {
     return __acpi_device_wakeup_enable(adev, target_state);
 }
 
 /**
  * acpi_device_wakeup_disable - Disable wakeup functionality for device.
  * @adev: ACPI device to disable wakeup functionality for.
  *
  * Disable the GPE associated with @adev and disable wakeup power for it.
  *
  * Callers must ensure that @adev is a valid ACPI device node before executing
  * this function.
  */
 static void acpi_device_wakeup_disable(struct acpi_device *adev)
 {
     struct acpi_device_wakeup *wakeup = &adev->wakeup;
 
     mutex_lock(&acpi_wakeup_lock);
 
     if (!wakeup->enable_count)
         goto out;
 
     acpi_disable_gpe(wakeup->gpe_device, wakeup->gpe_number);
     acpi_disable_wakeup_device_power(adev);
 
     wakeup->enable_count--;
 
 out:
     mutex_unlock(&acpi_wakeup_lock);
 }
 
 /**
  * acpi_pm_set_device_wakeup - Enable/disable remote wakeup for given device.
  * @dev: Device to enable/disable to generate wakeup events.
  * @enable: Whether to enable or disable the wakeup functionality.
  */
 int acpi_pm_set_device_wakeup(struct device *dev, bool enable)
 {
     struct acpi_device *adev;
     int error;
 
     adev = ACPI_COMPANION(dev);
     if (!adev) {
         dev_dbg(dev, "ACPI companion missing in %s!\n", __func__);
         return -ENODEV;
     }
 
     if (!acpi_device_can_wakeup(adev))
         return -EINVAL;
 
     if (!enable) {
         acpi_device_wakeup_disable(adev);
         dev_dbg(dev, "Wakeup disabled by ACPI\n");
         return 0;
     }
 
     error = __acpi_device_wakeup_enable(adev, acpi_target_system_state());
     if (!error)
         dev_dbg(dev, "Wakeup enabled by ACPI\n");
 
     return error;
 }
 EXPORT_SYMBOL_GPL(acpi_pm_set_device_wakeup);
 
 /**
  * acpi_dev_pm_low_power - Put ACPI device into a low-power state.
  * @dev: Device to put into a low-power state.
  * @adev: ACPI device node corresponding to @dev.
  * @system_state: System state to choose the device state for.
  */
 static int acpi_dev_pm_low_power(struct device *dev, struct acpi_device *adev,
                  u32 system_state)
 {
     int ret, state;
 
     if (!acpi_device_power_manageable(adev))
         return 0;
 
     ret = acpi_dev_pm_get_state(dev, adev, system_state, NULL, &state);
     return ret ? ret : acpi_device_set_power(adev, state);
 }
 
 /**
  * acpi_dev_pm_full_power - Put ACPI device into the full-power state.
  * @adev: ACPI device node to put into the full-power state.
  */
 static int acpi_dev_pm_full_power(struct acpi_device *adev)
 {
     return acpi_device_power_manageable(adev) ?
         acpi_device_set_power(adev, ACPI_STATE_D0) : 0;
 }
 
 /**
  * acpi_dev_suspend - Put device into a low-power state using ACPI.
  * @dev: Device to put into a low-power state.
  * @wakeup: Whether or not to enable wakeup for the device.
  *
  * Put the given device into a low-power state using the standard ACPI
  * mechanism.  Set up remote wakeup if desired, choose the state to put the
  * device into (this checks if remote wakeup is expected to work too), and set
  * the power state of the device.
  */
 int acpi_dev_suspend(struct device *dev, bool wakeup)
 {
     struct acpi_device *adev = ACPI_COMPANION(dev);
     u32 target_state = acpi_target_system_state();
     int error;
 
     if (!adev)
         return 0;
 
     if (wakeup && acpi_device_can_wakeup(adev)) {
         error = acpi_device_wakeup_enable(adev, target_state);
         if (error)
             return -EAGAIN;
     } else {
         wakeup = false;
     }
 
     error = acpi_dev_pm_low_power(dev, adev, target_state);
     if (error && wakeup)
         acpi_device_wakeup_disable(adev);
 
     return error;
 }
 EXPORT_SYMBOL_GPL(acpi_dev_suspend);
 
 /**
  * acpi_dev_resume - Put device into the full-power state using ACPI.
  * @dev: Device to put into the full-power state.
  *
  * Put the given device into the full-power state using the standard ACPI
  * mechanism.  Set the power state of the device to ACPI D0 and disable wakeup.
  */
 int acpi_dev_resume(struct device *dev)
 {
     struct acpi_device *adev = ACPI_COMPANION(dev);
     int error;
 
     if (!adev)
         return 0;
 
     error = acpi_dev_pm_full_power(adev);
     acpi_device_wakeup_disable(adev);
     return error;
 }
 EXPORT_SYMBOL_GPL(acpi_dev_resume);
 
 /**
  * acpi_subsys_runtime_suspend - Suspend device using ACPI.
  * @dev: Device to suspend.
  *
  * Carry out the generic runtime suspend procedure for @dev and use ACPI to put
  * it into a runtime low-power state.
  */
 int acpi_subsys_runtime_suspend(struct device *dev)
 {
     int ret = pm_generic_runtime_suspend(dev);
 
     return ret ? ret : acpi_dev_suspend(dev, true);
 }
 EXPORT_SYMBOL_GPL(acpi_subsys_runtime_suspend);
 
 /**
  * acpi_subsys_runtime_resume - Resume device using ACPI.
  * @dev: Device to Resume.
  *
  * Use ACPI to put the given device into the full-power state and carry out the
  * generic runtime resume procedure for it.
  */
 int acpi_subsys_runtime_resume(struct device *dev)
 {
     int ret = acpi_dev_resume(dev);
 
     return ret ? ret : pm_generic_runtime_resume(dev);
 }
 EXPORT_SYMBOL_GPL(acpi_subsys_runtime_resume);
 
 #ifdef CONFIG_PM_SLEEP
 static bool acpi_dev_needs_resume(struct device *dev, struct acpi_device *adev)
 {
     u32 sys_target = acpi_target_system_state();
     int ret, state;
 
     if (!pm_runtime_suspended(dev) || !adev || (adev->wakeup.flags.valid &&
         device_may_wakeup(dev) != !!adev->wakeup.prepare_count))
         return true;
 
     if (sys_target == ACPI_STATE_S0)
         return false;
 
     if (adev->power.flags.dsw_present)
         return true;
 
     ret = acpi_dev_pm_get_state(dev, adev, sys_target, NULL, &state);
     if (ret)
         return true;
 
     return state != adev->power.state;
 }
 
 /**
  * acpi_subsys_prepare - Prepare device for system transition to a sleep state.
  * @dev: Device to prepare.
  */
 int acpi_subsys_prepare(struct device *dev)
 {
     struct acpi_device *adev = ACPI_COMPANION(dev);
 
     if (dev->driver && dev->driver->pm && dev->driver->pm->prepare) {
         int ret = dev->driver->pm->prepare(dev);
 
         if (ret < 0)
             return ret;
 
         if (!ret && dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_PREPARE))
             return 0;
     }
 
     return !acpi_dev_needs_resume(dev, adev);
 }
 EXPORT_SYMBOL_GPL(acpi_subsys_prepare);
 
 /**
  * acpi_subsys_complete - Finalize device's resume during system resume.
  * @dev: Device to handle.
  */
 void acpi_subsys_complete(struct device *dev)
 {
     pm_generic_complete(dev);
     /*
      * If the device had been runtime-suspended before the system went into
      * the sleep state it is going out of and it has never been resumed till
      * now, resume it in case the firmware powered it up.
      */
     if (pm_runtime_suspended(dev) && pm_resume_via_firmware())
         pm_request_resume(dev);
 }
 EXPORT_SYMBOL_GPL(acpi_subsys_complete);
 
 /**
  * acpi_subsys_suspend - Run the device driver's suspend callback.
  * @dev: Device to handle.
  *
  * Follow PCI and resume devices from runtime suspend before running their
  * system suspend callbacks, unless the driver can cope with runtime-suspended
  * devices during system suspend and there are no ACPI-specific reasons for
  * resuming them.
  */
 int acpi_subsys_suspend(struct device *dev)
 {
     if (!dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_SUSPEND) ||
         acpi_dev_needs_resume(dev, ACPI_COMPANION(dev)))
         pm_runtime_resume(dev);
 
     return pm_generic_suspend(dev);
 }
 EXPORT_SYMBOL_GPL(acpi_subsys_suspend);
 
 /**
  * acpi_subsys_suspend_late - Suspend device using ACPI.
  * @dev: Device to suspend.
  *
  * Carry out the generic late suspend procedure for @dev and use ACPI to put
  * it into a low-power state during system transition into a sleep state.
  */
 int acpi_subsys_suspend_late(struct device *dev)
 {
     int ret;
 
     if (dev_pm_skip_suspend(dev))
         return 0;
 
     ret = pm_generic_suspend_late(dev);
     return ret ? ret : acpi_dev_suspend(dev, device_may_wakeup(dev));
 }
 EXPORT_SYMBOL_GPL(acpi_subsys_suspend_late);
 
 /**
  * acpi_subsys_suspend_noirq - Run the device driver's "noirq" suspend callback.
  * @dev: Device to suspend.
  */
 int acpi_subsys_suspend_noirq(struct device *dev)
 {
     int ret;
 
     if (dev_pm_skip_suspend(dev))
         return 0;
 
     ret = pm_generic_suspend_noirq(dev);
     if (ret)
         return ret;
 
     /*
      * If the target system sleep state is suspend-to-idle, it is sufficient
      * to check whether or not the device's wakeup settings are good for
      * runtime PM.  Otherwise, the pm_resume_via_firmware() check will cause
      * acpi_subsys_complete() to take care of fixing up the device's state
      * anyway, if need be.
      */
     if (device_can_wakeup(dev) && !device_may_wakeup(dev))
         dev->power.may_skip_resume = false;
 
     return 0;
 }
 EXPORT_SYMBOL_GPL(acpi_subsys_suspend_noirq);
 
 /**
  * acpi_subsys_resume_noirq - Run the device driver's "noirq" resume callback.
  * @dev: Device to handle.
  */
 static int acpi_subsys_resume_noirq(struct device *dev)
 {
     if (dev_pm_skip_resume(dev))
         return 0;
 
     return pm_generic_resume_noirq(dev);
 }
 
 /**
  * acpi_subsys_resume_early - Resume device using ACPI.
  * @dev: Device to Resume.
  *
  * Use ACPI to put the given device into the full-power state and carry out the
  * generic early resume procedure for it during system transition into the
  * working state, but only do that if device either defines early resume
  * handler, or does not define power operations at all. Otherwise powering up
  * of the device is postponed to the normal resume phase.
  */
 static int acpi_subsys_resume_early(struct device *dev)
 {
     const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
     int ret;
 
     if (dev_pm_skip_resume(dev))
         return 0;
 
     if (pm && !pm->resume_early) {
         dev_dbg(dev, "postponing D0 transition to normal resume stage\n");
         return 0;
     }
 
     ret = acpi_dev_resume(dev);
     return ret ? ret : pm_generic_resume_early(dev);
 }
 
 /**
  * acpi_subsys_resume - Resume device using ACPI.
  * @dev: Device to Resume.
  *
  * Use ACPI to put the given device into the full-power state if it has not been
  * powered up during early resume phase, and carry out the generic resume
  * procedure for it during system transition into the working state.
  */
 static int acpi_subsys_resume(struct device *dev)
 {
     const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
     int ret = 0;
 
     if (!dev_pm_skip_resume(dev) && pm && !pm->resume_early) {
         dev_dbg(dev, "executing postponed D0 transition\n");
         ret = acpi_dev_resume(dev);
     }
 
     return ret ? ret : pm_generic_resume(dev);
 }
 
 /**
  * acpi_subsys_freeze - Run the device driver's freeze callback.
  * @dev: Device to handle.
  */
 int acpi_subsys_freeze(struct device *dev)
 {
     /*
      * Resume all runtime-suspended devices before creating a snapshot
      * image of system memory, because the restore kernel generally cannot
      * be expected to always handle them consistently and they need to be
      * put into the runtime-active metastate during system resume anyway,
      * so it is better to ensure that the state saved in the image will be
      * always consistent with that.
      */
     pm_runtime_resume(dev);
 
     return pm_generic_freeze(dev);
 }
 EXPORT_SYMBOL_GPL(acpi_subsys_freeze);
 
 /**
  * acpi_subsys_restore_early - Restore device using ACPI.
  * @dev: Device to restore.
  */
 int acpi_subsys_restore_early(struct device *dev)
 {
     int ret = acpi_dev_resume(dev);
 
     return ret ? ret : pm_generic_restore_early(dev);
 }
 EXPORT_SYMBOL_GPL(acpi_subsys_restore_early);
 
 /**
  * acpi_subsys_poweroff - Run the device driver's poweroff callback.
  * @dev: Device to handle.
  *
  * Follow PCI and resume devices from runtime suspend before running their
  * system poweroff callbacks, unless the driver can cope with runtime-suspended
  * devices during system suspend and there are no ACPI-specific reasons for
  * resuming them.
  */
 int acpi_subsys_poweroff(struct device *dev)
 {
     if (!dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_SUSPEND) ||
         acpi_dev_needs_resume(dev, ACPI_COMPANION(dev)))
         pm_runtime_resume(dev);
 
     return pm_generic_poweroff(dev);
 }
 EXPORT_SYMBOL_GPL(acpi_subsys_poweroff);
 
 /**
  * acpi_subsys_poweroff_late - Run the device driver's poweroff callback.
  * @dev: Device to handle.
  *
  * Carry out the generic late poweroff procedure for @dev and use ACPI to put
  * it into a low-power state during system transition into a sleep state.
  */
 static int acpi_subsys_poweroff_late(struct device *dev)
 {
     int ret;
 
     if (dev_pm_skip_suspend(dev))
         return 0;
 
     ret = pm_generic_poweroff_late(dev);
     if (ret)
         return ret;
 
     return acpi_dev_suspend(dev, device_may_wakeup(dev));
 }
 
 /**
  * acpi_subsys_poweroff_noirq - Run the driver's "noirq" poweroff callback.
  * @dev: Device to suspend.
  */
 static int acpi_subsys_poweroff_noirq(struct device *dev)
 {
     if (dev_pm_skip_suspend(dev))
         return 0;
 
     return pm_generic_poweroff_noirq(dev);
 }
 #endif /* CONFIG_PM_SLEEP */
 
 static struct dev_pm_domain acpi_general_pm_domain = {
     .ops = {
         .runtime_suspend = acpi_subsys_runtime_suspend,
         .runtime_resume = acpi_subsys_runtime_resume,
 #ifdef CONFIG_PM_SLEEP
         .prepare = acpi_subsys_prepare,
         .complete = acpi_subsys_complete,
         .suspend = acpi_subsys_suspend,
         .resume = acpi_subsys_resume,
         .suspend_late = acpi_subsys_suspend_late,
         .suspend_noirq = acpi_subsys_suspend_noirq,
         .resume_noirq = acpi_subsys_resume_noirq,
         .resume_early = acpi_subsys_resume_early,
         .freeze = acpi_subsys_freeze,
         .poweroff = acpi_subsys_poweroff,
         .poweroff_late = acpi_subsys_poweroff_late,
         .poweroff_noirq = acpi_subsys_poweroff_noirq,
         .restore_early = acpi_subsys_restore_early,
 #endif
     },
 };
 
 /**
  * acpi_dev_pm_detach - Remove ACPI power management from the device.
  * @dev: Device to take care of.
  * @power_off: Whether or not to try to remove power from the device.
  *
  * Remove the device from the general ACPI PM domain and remove its wakeup
  * notifier.  If @power_off is set, additionally remove power from the device if
  * possible.
  *
  * Callers must ensure proper synchronization of this function with power
  * management callbacks.
  */
 static void acpi_dev_pm_detach(struct device *dev, bool power_off)
 {
     struct acpi_device *adev = ACPI_COMPANION(dev);
 
     if (adev && dev->pm_domain == &acpi_general_pm_domain) {
         dev_pm_domain_set(dev, NULL);
         acpi_remove_pm_notifier(adev);
         if (power_off) {
             /*
              * If the device's PM QoS resume latency limit or flags
              * have been exposed to user space, they have to be
              * hidden at this point, so that they don't affect the
              * choice of the low-power state to put the device into.
              */
             dev_pm_qos_hide_latency_limit(dev);
             dev_pm_qos_hide_flags(dev);
             acpi_device_wakeup_disable(adev);
             acpi_dev_pm_low_power(dev, adev, ACPI_STATE_S0);
         }
     }
 }
 
 /**
  * acpi_dev_pm_attach - Prepare device for ACPI power management.
  * @dev: Device to prepare.
  * @power_on: Whether or not to power on the device.
  *
  * If @dev has a valid ACPI handle that has a valid struct acpi_device object
  * attached to it, install a wakeup notification handler for the device and
  * add it to the general ACPI PM domain.  If @power_on is set, the device will
  * be put into the ACPI D0 state before the function returns.
  *
  * This assumes that the @dev's bus type uses generic power management callbacks
  * (or doesn't use any power management callbacks at all).
  *
  * Callers must ensure proper synchronization of this function with power
  * management callbacks.
  */
 int acpi_dev_pm_attach(struct device *dev, bool power_on)
 {
     /*
      * Skip devices whose ACPI companions match the device IDs below,
      * because they require special power management handling incompatible
      * with the generic ACPI PM domain.
      */
     static const struct acpi_device_id special_pm_ids[] = {
         ACPI_FAN_DEVICE_IDS,
         {}
     };
     struct acpi_device *adev = ACPI_COMPANION(dev);
 
     if (!adev || !acpi_match_device_ids(adev, special_pm_ids))
         return 0;
 
     /*
      * Only attach the power domain to the first device if the
      * companion is shared by multiple. This is to prevent doing power
      * management twice.
      */
     if (!acpi_device_is_first_physical_node(adev, dev))
         return 0;
 
     acpi_add_pm_notifier(adev, dev, acpi_pm_notify_work_func);
     dev_pm_domain_set(dev, &acpi_general_pm_domain);
     if (power_on) {
         acpi_dev_pm_full_power(adev);
         acpi_device_wakeup_disable(adev);
     }
 
     dev->pm_domain->detach = acpi_dev_pm_detach;
     return 1;
 }
 EXPORT_SYMBOL_GPL(acpi_dev_pm_attach);
 
 /**
  * acpi_storage_d3 - Check if D3 should be used in the suspend path
  * @dev: Device to check
  *
  * Return %true if the platform firmware wants @dev to be programmed
  * into D3hot or D3cold (if supported) in the suspend path, or %false
  * when there is no specific preference. On some platforms, if this
  * hint is ignored, @dev may remain unresponsive after suspending the
  * platform as a whole.
  *
  * Although the property has storage in the name it actually is
  * applied to the PCIe slot and plugging in a non-storage device the
  * same platform restrictions will likely apply.
  */
 bool acpi_storage_d3(struct device *dev)
 {
     struct acpi_device *adev = ACPI_COMPANION(dev);
     u8 val;
 
     if (force_storage_d3())
         return true;
 
     if (!adev)
         return false;
     if (fwnode_property_read_u8(acpi_fwnode_handle(adev), "StorageD3Enable",
             &val))
         return false;
     return val == 1;
 }
 EXPORT_SYMBOL_GPL(acpi_storage_d3);
 
 /**
  * acpi_dev_state_d0 - Tell if the device is in D0 power state
  * @dev: Physical device the ACPI power state of which to check
  *
  * On a system without ACPI, return true. On a system with ACPI, return true if
  * the current ACPI power state of the device is D0, or false otherwise.
  *
  * Note that the power state of a device is not well-defined after it has been
  * passed to acpi_device_set_power() and before that function returns, so it is
  * not valid to ask for the ACPI power state of the device in that time frame.
  *
  * This function is intended to be used in a driver's probe or remove
  * function. See Documentation/firmware-guide/acpi/low-power-probe.rst for
  * more information.
  */
 bool acpi_dev_state_d0(struct device *dev)
 {
     struct acpi_device *adev = ACPI_COMPANION(dev);
 
     if (!adev)
         return true;
 
     return adev->power.state == ACPI_STATE_D0;
 }
 EXPORT_SYMBOL_GPL(acpi_dev_state_d0);
 
 #endif /* CONFIG_PM */

This page was automatically generated by the 2.1.0 LXR engine. The LXR team